INHIBITION OF SARCOPLASMIC-RETICULUM CA2+-ATPASE ACTIVITY BY CADMIUM, LEAD AND MERCURY

被引：81

作者：

HECHTENBERG, S ^{[1
]}

BEYERSMANN, D ^{[1
]}

机构：

[1] UNIV BREMEN, INST ZELLBIOL BIOCHEM & BIOTECHNOL, FACHBEREICH 2, LEOBENER STR NW2, W-2800 BREMEN 33, GERMANY

来源：

ENZYME | 1991年 / 45卷 / 03期

关键词：

CA2+-ATPASE; SARCOPLASMIC RETICULUM; CADMIUM; LEAD; MERCURY;

D O I：

10.1159/000468875

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The effect of Cd2+, Pb2+ and Hg2+ on the Ca2+-ATPase activity of sarcoplasmic reticulum from rabbit muscle was studied. The concentration of relevant free and complex species for the assay conditions have been computed. As a result, ATP hydrolysis was found to be inhibited with an IC50 value of 950 nmol/l free Cd2+ or 95 nmol/l free Pb2+. Although calculation of the free Hg2+ was not possible, the comparison of the IC50 values for total metal ions show that Hg2+ is the strongest inhibitor of enzyme activity. The inhibition by Cd2+ seems to be independent of substrate concentration, whereas the inhibitory effect of Pb2+ is lowered in the presence of higher MgATP concentrations. Our data illustrate that the three heavy metals are potent inhibitors of the Ca2+ pump. Therefore low concentrations of these metal ions may disturb intracellular Ca2+ homeostasis and act on Ca2+-mediated cell functions.

引用

页码：109 / 115

页数：7

共 22 条

[1] INTERACTION OF CD-2+ WITH THE CALMODULIN-ACTIVATED (CA-2+ + MG-2+)-ATPASE ACTIVITY OF HUMAN-ERYTHROCYTE GHOSTS [J].